Hasinoff et al., “Multiple-Aperture Photography for High Dynamic Range and post-Capture Refocusing”, IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 1, No. 1, January 2009 describes a method of generating a HDR (high dynamic range) image on the basis of time-sequentially captured images using a variable aperture. F. Guichard et al., “Extended Depth-of-Field using Sharpness Transport across Colour Channels”, SPIE, Proceedings of Electronic Imaging, 2009, refers to a method of obtaining images with extended depth-of-field where, for a given object distance, at least one colour plane of an RGB image contains the in-focus scene information.